Varieties of the colorred may differ in hue, chroma (also called saturation, intensity, or colorfulness) or lightness (or value, tone, or brightness), or in two or three of these qualities. Variations in value are also called tints and shades, a tint being a red or other hue mixed with white, a shade being mixed with black. A large selection of these various colors is shown below.

The color displayed at right, Red (RGB), RGB red, or electric red (i.e., as opposed to pigment red, shown below) is the brightest possible red that can be reproduced on a computer monitor. This color is an approximation of an orangish red spectral color. It is one of the three primary colors of light in the RGB color model, along with green and blue. The three additive primaries in the RGB color system are the three colors of light chosen such as to provide the maximum gamut of colors that are capable of being represented on a computer or television set, at a reasonable expense of power. Portable devices such as mobile phones might have even narrower gamut due to this purity–power tradeoff and their "red" may be less colorful and more orangish than the standard red of sRGB.

Pigment red is the color red that is achieved by mixing process (printer's) magenta and process (printer's) yellow in equal proportions. This is the color red that is shown in the diagram located at the bottom of the following website offering tintbooks for CMYK printing: [1].

The purpose of the CMYK color system is to provide the maximum possible gamut of colors capable of being reproduced in printing.

Psychedelic art made people used to brighter colors of red, and pigment colors or colored pencils called "true red" are produced by mixing pigment red with a tiny amount of white. The result approximates (with much less brightness that is possible on a computer screen) the electric red shown above.

The hues of the Munsell color system, at varying values, and maximum chroma to stay in the sRGB gamut.

The color defined as red in the Munsell color system (Munsell 5R) is shown at right. The Munsell color system is a color space that specifies colors based on three color dimensions: hue, value (lightness), and chroma (color purity), spaced uniformly in three dimensions in the elongated oval at an angle shaped Munsell color solid according to the logarithmic scale which governs human perception. In order for all the colors to be spaced uniformly, it was found necessary to use a color wheel with five primary colors—red, yellow, green, blue, and purple.

The Munsell colors displayed are only approximate as they have been adjusted to fit into the sRGB gamut.

Scarlet is a bright red with a slightly orange tinge. According to surveys in Europe and the United States, scarlet and other bright shades of red are the colors most associated with courage, force, passion, heat, and joy.[11] In the Roman Catholic Church, scarlet is the color worn by a cardinal, and is associated with the blood of Christ and the Christian martyrs, and with sacrifice.

Spanish red is the color that is called Rojo (the Spanish word for "red") in the Guía de coloraciones (Guide to colorations) by Rosa Gallego and Juan Carlos Sanz, a color dictionary published in 2005 that is widely popular in the Hispanophone realm.

The color carmine is a saturated red. In its pigment form it mostly contains the red light with wavelengths longer than 600 nm, i.e. it is close to the extreme spectral red. This places it far beyond standard gamuts (both RGB and CMYK), and given RGB value is a poor approximation only.

OU Crimson, along with Cream, are the official colors for The University of Oklahoma, and its athletic teams, the Oklahoma Sooners. In the fall of 1895, Miss May Overstreet was asked to chair a committee to select the colors of the university. The committee decided the colors should be crimson and cream and an elaborate display of the colors was draped above a platform before the student body.[28]

This is one of the colors on one of the milk paint color lists, paint colors formulated to reproduce the colors historically used on the American frontier and made, like those paints were, with milk. This color is mixed with various amounts of white paint to create any desired shade of the color barn red.[31]

^The color displayed in the color box above matches the color called imperial red in the 1930 book by Maerz and Paul A Dictionary of Color New York:1930 McGraw-Hill; the color imperial red is displayed on page 27, Plate 2, Color Sample L11.

^The color displayed in the color box above matches the color called ruby in the 1930 book by Maerz and Paul A Dictionary of Color New York:1930 McGraw-Hill; the color ruby is displayed on page 35, Plate 6, Color Sample G6.